Conservatory roofs may be constructed in a number of different ways. Traditionally, timber members have been cut on site to the required size and were nailed or screwed together. Glazing was then fitted to the glazing bars extending from a ridge beam down to a wall plate, laid around the upper surface of the conservatory walls. Many modern conservatory roofs are now assembled from pre-formed metal sections, either cut remote from the location at which the roof is to be constructed and then assembled on site, or cut and assembled on site, as appropriate, whereafter multi-wall plastics sheeting is fitted to the glazing bars to complete the roof.
A particular problem arises in the construction of a conservatory having a hip roof. Such a roof usually is formed at an end of a conservatory where there are two parallel spaced-apart walls and a further wall extending at right-angles between the parallel walls. The hip roof has a panel of triangular shape which extends upwardly at an acute angle to the horizontal, from the further wall to the ridge beam. A hip bar extends along the junction between the hip end and the side panels of the roof, and--depending upon the various dimensions of the roof--one or more glazing bars, either on the hip end or the main area of the roof, may need to connect to the hip bars. Such glazing bars are usually referred to as "jack-rafters".
In the case of a hip roof constructed from metal members, a particular problem arises in the connection of the jack-rafters to the hip bar. The precise angle between the upper end of each jack-rafter and the hip bar is difficult to pre-define and it is necessary to provide some kind of adjustable connection, which may be made to the hip bar at the required point, during construction on-site. Typically, an engineered pivoting bracket is employed, which is bolted to the hip bar in a fixed position. Once fixed, it is very difficult to make minor adjustments to the position, if--as frequently occurs--during final assembly of the roof, the jack-rafter is not located precisely where it was anticipated it would be located.